Module jamal.core
Package javax0.jamal.builtins

Class Env

java.lang.Object
javax0.jamal.builtins.Env
All Implemented Interfaces:
javax0.jamal.api.Identified, javax0.jamal.api.Macro, javax0.jamal.api.ServiceLoaded
public class Env extends Object implements javax0.jamal.api.Macro
Get the value of an environment variable. For example, 

 {@env JAVA_HOME}

will result the current value of the environment variable JAVA_HOME.

If there is a ? after the name then the macro returns "true" (string without the quotes) if the environment variable is defined and "false" if it is not defined. Testing just the value of the environment variable in an if macro may be misleading in case the value of the environment variable is true or false or empty string.

If there is a ! after the name then the macro will throw an exception in case the environment variable is not defined.

The input of the macro is trimmed at the start, so starting and ending spaces do not count. If the last character after the trimming is ? or ! it is chopped off and the string is chopped again. It means that you can have spaces between the name and the ? or ! character.

You cannot have both ? and ! characters. If your environment variable name ends with the ? or ! character then you cannot use this macro, and you are in trouble. However, in that case you are a sick bastard, and you are in trouble anyway.

  • Nested Class Summary

    Nested classes/interfaces inherited from interface javax0.jamal.api.Identified

    javax0.jamal.api.Identified.Undefined

    Nested classes/interfaces inherited from interface javax0.jamal.api.Macro

    javax0.jamal.api.Macro.Stateful

  • Field Summary

    Fields inherited from interface javax0.jamal.api.Identified

    DEFAULT_MACRO, MACRO_NAME_ARG1, MACRO_NAME_ARG2

    Fields inherited from interface javax0.jamal.api.Macro

    FETCH

  • Constructor Summary

    Constructors
    Constructor
    Description
    Env()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    evaluate(javax0.jamal.api.Input in, javax0.jamal.api.Processor processor)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface javax0.jamal.api.Macro

    fetch, getId, getIds, prefetch

  • Constructor Details

    • Env

      public Env()

  • Method Details

    • evaluate

      public String evaluate(javax0.jamal.api.Input in, javax0.jamal.api.Processor processor) throws javax0.jamal.api.BadSyntax
      Specified by:
      evaluate in interface javax0.jamal.api.Macro
      Throws:
      javax0.jamal.api.BadSyntax